In most industries, systems are mandatory for cleaning air and related gases laden with dust or other particulate matter generated by the industrial processes and the combustion of solid fuel. Prior art devices for meeting the filtering needs of such industries have included what are termed "baghouses" or "filterhouses". However, such prior art devices have significant drawbacks in that the filter bags and supporting frames are bulky, difficult to install and replace, and subject to damage and rapid wear. The housing for such filter elements occupies considerable space which often could be put to more valuable use. To improve upon such prior art devices, efforts have been directed to reducing the size of the air filters used. Pleated paper filter elements such as taught in U.S. Pat. No. 4,218,227 to Frey for a "Dust Collector" have brought the art closer to achieving reduced space requirements while maintaining effective filtering capacities. However, the industry need for a more compact filter assembly with even greater filtering capacity remains.
For example, the large prior art devices have physical volume requirements for their air cleaning and hopper space of about one-twentieth of the volume of fluid cleaned per minute. Stated differently, such devices have a cleaning capacity of twenty, or even much less, cfm per cubic foot. When an industry requires one hundred thousand to one million cubic feet of fluid to be cleaned each minute, the larger prior art devices become gigantic structures whose volume requirements may even surpass the volume of the dust-generating facility. Further, the cost of purchase, installation, and connection of such devices may be prohibitive in view of present day environmental regulations. It is not unusual for a company to shut down its operation in order to avoid the prohibitive costs for installing such prior art devices.
What is needed then in such industries is an apparatus and method for obtaining a much greater cleaning capacity, along with a reduction in the housing volume required for the filter assembly, than has to date been possible with the prior art devices. The present invention achieves this objective and includes features which combine to provide an air filtering assembly having a cleaning capacity of at least forty to fifty or more cfm per cubic foot of volume, with a remarkably compact and serviceable design and arrangement.